Implications of Unequal-Mass Kinematics for the Regge-Pole Model of Vector-Meson Production

Abstract

Application of the Regge-pole model to vector-meson production by incident pseudoscalars is reexamined in the light of recent theoretical advances in the treatment of unequal-mass processes. It is found that in the absence of conspiracy between trajectories at $t=0\mathrm{}$, the kinematic factors separated from the helicity amplitudes before Reggeization tend to suppress the effects of parity = ${\mathrm{}(-1\mathrm{})\mathrm{}}^J$ exchanges relative to parity = ${\mathrm{}(-1\mathrm{})\mathrm{}}^{J+1\mathrm{}}$ contributions, in the region $\mathrm{}\left|t\right|\mathrm{}\le 0.2$ Ge${\mathrm{V}}^2$. This helps account for the experimental observation that, although ${\alpha }_{\pi }$ is less than ${\alpha }_{A2\mathrm{}},{\alpha }_{\omega }\cdots$, $\pi$ exchange tends to dominate the forward peak wherever it is possible (production of $\rho$ and $K^{*}$ mesons). This kinematic suppression also helps explain the failure of $\rho$ exchange to dominate in $\omega$ production.